The overarching goal of this study is to advance understanding of alcohol treatment outcome. This study will focus on four aspects of treatment outcome: 1) client perceived influences of relapse onset 2) client perceived influences of relapse termination 3) client perceived influences of periods of abstinence, and 4) temporal and alcohol-related parameters of relapse. Whereas relapse onset has received considerable attention in alcohol research, relapse termination and abstinence maintenance have received less attention. Since a data set is readily available (the Project MATCH data base; N = 1726) to do this, the cost of this study will be reduced considerably. The Relapse Questionnaire was administered in Project MATCH at the posttreatment, 6, and 12-month follow-ups. This Questionnaire consists of three sectiOns, which multidimensionally assess characteristics of relapse onset, relapse termination, and abstinence maintenance. The aims of the study are 1) to empirically determine the underlying structure of each section of this questionnaire, 2) to determine the interrelationships of temporal and alcohol-related parameters of relapse, 3) to determine the interrelationships of relapse onset, relapse termination and abstinence maintenance characteristics and the relationships of these three domains to temporal and alcohol- related parameters of relapse and general treatment outcome, 4) to determine the consistency of relapse onset, relapse termination, and abstinence maintenance over time, and to examine how consistency and changes in relapse onset and abstinence maintenance are related to treatment outcome, and 5) to examine the generalizability of the Relapse Questionnaire scales across Clinical Research Units, treatments, gender, and ethnicity. These analyses will have many implications regarding ways in which alcohol treatment can become more effective. For instance, the most dangerous relapse onset characteristics will be identified, the most efficacious abstinence maintenance methods will be identified, and the prognostic value of pretreatment relapse termination characteristics will be ascertained.